Elongated medical devices are commonly used to facilitate navigation through and/or treatment within the anatomy of a patient. A variety of elongate medical devices for intracorporeal use, such as catheters, endoscopes, guidewires and the like, have been developed over the past several decades. Because the anatomy of a patient may be very tortuous, it is often desirable to combine a number of performance features in such devices. For example, it is sometimes desirable that the device have a relatively high level of pushability and torqueability, particularly near its proximal end. It is also sometimes desirable that a device be relatively flexible, particularly near its distal end.
A number of different elongated medical device structures and assemblies are known, each having certain advantages and disadvantages. However, there is an ongoing need to provide alternative elongated medical device structures, assemblies, and methods.
One such elongate medical device, a balloon catheter, can include an inflatable and deflatable balloon carried by a long narrow catheter body. The balloon is initially folded around the catheter body to reduce the radial profile of the balloon catheter for easy insertion into the body. During use, the balloon may be inflated and later deflated at a selected location within the body.
One common balloon catheter design includes a coaxial arrangement of an inner tubular member surrounded by an outer tubular member. The inner tubular member typically includes a lumen that can be used for delivery of the device over a guidewire. The annular space between the inner tubular member and the outer tubular member typically defines an inflation lumen in fluid communication with the balloon, wherein an inflation fluid passes through during inflation and deflation of the balloon. It is important that the inflation lumen remain substantially open and unobstructed during inflation and deflation of the balloon to insure proper inflation and deflation of the balloon.
Some such catheters may utilize tubular members having multiple sections of dissimilar materials joined together by thermally bonding the sections together to provide regions of varying flexibility. There is an ongoing need to provide new structures and methods of joining multiple sections of a catheter shaft without compromising the desired characteristics of the catheter shaft.